We've all seen it. Someone bellies up to the fast food counter and orders a Whopper with cheese, large fries and diet soda — as if a zero-calorie chaser can compensate for the 1,300 calorie overload. Or are you guilty of scarfing down a whole big bag of Nacho Cheese Doritos and a Diet Mountain Dew?

Many of us justify a diet drink habit as a way to cut calories and lose weight. For some it can work, at least for awhile.

“Swapping sugary, high calorie beverages for low- or no-calorie artificially sweetened beverages like diet soda can potentially help you cut calories and lose weight,” says Marisa Moore, R.D., a spokesperson for the American Dietetic Association. But the most important thing is to pay attention to total calorie intake, she adds.

Americans are drinking lots of diet sodas — regular consumers average 27 ounces, or slightly more than 2 cans, daily, according to research — and gobble up more artificial sweeteners in cookies, yogurt and other products,
obesity rates have soared
.

Substituting a soda with artificial sweeteners for a sugary beverage can help lower calorie intake, but there’s no evidence it helps you keep off the pounds in the long-term, a recent review of hundreds of studies on non-calorie sweeteners, appetite and food intake published in the American Journal of Clinical Nutrition indicated.

In fact, two recent studies found that being a diet soda junkie could actually put you at a
greater risk of weight gain
. Normal weight people who drank 3 servings or more of diet soda a day — at least 21 weekly servings — were at almost double the risk for becoming overweight or obese after seven to eight years compared to people who skipped diet drinks, according to researchers at the University of Texas Health Science Center at San Antonio. And people who consumed at least one daily serving of diet soda (versus none) were more likely to develop a high waist circumference, a condition linked with diabetes, hypertension and cardiovascular disease, according to a recent study.

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

The American Dietetic Association says there's no conclusive evidence that diet sodas directly cause weight gain, but at least one expert believes an artificial sweetener habit may overstimulate our taste receptors for sweetness. Dr. David Ludwig, director of the Optimal Weight for Life Program at Children’s Hospital in Boston, cites animal studies that suggest consuming diet drinks alone (not with food) can confuse or disrupt the body’s ability to determine calorie content based on sweetness. As a result, the hyped-up sugar receptors could increase hunger and food intake, and contribute to weight gain. People would crave more high-calorie sweet foods and
fewer healthful, less sweet foods
, such as fruits, vegetables, and legumes.

“Even if diet drinks prove to aid long-term weight loss when used to replace sugary beverages, they may promote weight gain when consumed instead of unsweetened beverages,” Ludwig wrote in a commentary last year in the Journal of the American Medical Association.

Of course, it’s possible that if people in the studies who drank diet soda didn’t do so, they might have gained even more weight, especially if instead they turned to sugary beverages or consumed food instead of the diet soda.

So, if you're used to drinking lots of sugary beverages, replacing them with a calorie-free soda might help kickstart weight loss. And if you eat a basically healthful diet with minimal amounts of sugary foods or artificial sweeteners, enjoying an occasional or even daily diet soda won't likely tip the scale.

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

For those who have health or other concerns and want to curb their diet soda habit, Moore suggests plain sparkling water (add fresh ginger or mint to make ginger ale); sparkling flavored waters made with no additives; and plain water spruced up with cucumber, orange, lemon or lime slices.

As for me, I admit not a day goes by that I don’t have a diet soda. But because emerging research suggests possible links between diet soda and metabolic syndrome, type 2 diabetes, kidney problems, and preterm delivery, it’s prudent if you’re more than an occasional diet soda consumer to curb intake. I try to drink a cup of water before I have any diet soda and buy one can at a time — instead of a 6-pack or case — to have at home or at my office. When eating out, I ask for tons of ice. Until more conclusive studies are done, I’m not convinced I need to kick the habit completely.

Elisa Zied, R.D. is the founder/president of Zied Health Communications, LLC and author of "Nutrition at Your Fingertips" and co-author of "Feed Your Family Right!" For more, visit elisazied.com